Controllable growth of nanocomposite films with metal nanocrystals sandwiched between dielectric superlattices

摘要

Nanocomposite films, with Ni nanocrystals (NCs) (5–8 nm) embedded within SrTiO₃/BaTiO₃ superlattice (period: 30 nm), were prepared by laser molecular beam epitaxy. In situ reflection high-energy electron diffraction was employed to study the role of lattice strain in the self-organization of NCs and the epitaxial growth of SrTiO₃/BaTiO₃ superlattice. It was found that the strain from large lattice mismatch drove the self-organization of Ni NCs. Also the SrTiO₃/BaTiO₃ epitaxial growth was achieved on the NC-dotted irregular interface, because the epitaxial growth occurred preferably at sites with low strain. The fine alternation of the two processes would provide a possible route to engineer controllably the nanocomposite microstructure.